The present invention relates to an impact adapter for transfer of impacts and rotation from an impact rock drilling machine to a drill string.
In previously known impact adapters ridges and grooves at the rear end of the impact adapter are used for transferring torque to a drill string from a driver journalled in the rock drilling machine. Because of manufacturing tolerances one has a certain play between the impact adapter and the driver in order to allow the axial movement caused by the impacts of the rock drilling machine against the impact adapter. This results in the impact adapter coming more or less obliquely in the driver. This oblique position in combination with the relative axial movement between the driver and the impact adapter often gives rise to breakage of one or more of the ridges adjacent the rear end of the impact adapter.